The present invention relates to a structure of a semiconductor device and a process for fabricating the same and, more particularly, to a large-capacity multi-chip semiconductor device which is enabled to have a memory capacity a plurality of times as large as that of a conventional IC package for the same mounting area by using film carriers.
A semiconductor memory is widely used in information devices such as a large-sized computer, a work station, a personal computer, a word processor or facsimile. The progressive performance and variety of these devices has resulted in an increased demand for the semiconductor memories to be used in the devices. In this meanwhile, the mounting area to be occupied by the semiconductor memories in a device requiring a memory of large capacity has tended to increase, which raises the largest factor of blocking the reduction in the size and weight of the device. In order to solve this problem, it has been accomplished in the prior art to increase the capacity of the memory per chip by highly integrating the in-chip elements, to mount the packaged semiconductor module highly densely in a print- circuit board and to stack a plurality of semiconductor chips highly densely in the direction of thickness. Of these, the highly dense mounting on the printed substrate is accomplished mainly by arraying a plurality of faced mounting type semiconductor devices or TABs (i.e., semiconductor devices prepared by connecting semiconductor chips with the leads of a tape carrier by the TAB (Tape Automated Bonding) method and by connecting the respective leads of the TABs with signal wires on the printed substrate. Moreover, the method of stacking the plural semiconductor chips in the direction of thickness is accomplished by connecting the respective outer leads of single modules directly with the printed substrate.
Incidentally, the papers relating to those techniques are exemplified by Japanese Patent Laid-Opens Nos. 59 - 194460, 61 - 101067 and 62 - 195138.